JP4353149B2 - Image forming apparatus and process cartridge - Google Patents

Description

The present invention relates to a so-called electrophotographic image forming apparatus that forms an image by developing an electrostatic latent image formed on an electrostatic latent image carrier with toner and attaching it to a recording medium, and the image forming device about the possible process cartridge used.

  Conventionally, an image bearing member on which an electrostatic latent image is formed on a surface, a toner cartridge in which toner used for developing the electrostatic latent image is stored, and a toner stored in the toner cartridge are rubbed together. A developing unit that charges and adheres to the surface of the image carrier and develops the electrostatic latent image; and a transfer unit that transfers the toner adhered to the surface of the image carrier by the developing unit to a recording medium. An image forming apparatus including a developing device in which the toner cartridge is detachable and at least the developing unit is accommodated is considered. In this type of image forming apparatus, when an electrostatic latent image is formed on the surface of the image carrier, the developing means frictionally charges the toner contained in the toner cartridge to adhere to the surface of the image carrier. The electrostatic latent image is developed. Subsequently, the toner adhering to the surface of the image carrier by the developing unit as described above is transferred to the recording medium by the transfer unit, so that an image corresponding to the electrostatic latent image is formed on the recording medium. Can be formed. Further, since the developing device containing the developing means is configured so that the toner cartridge can be attached and detached, the toner cartridge can be replaced when the toner is consumed, and image formation can be continued.

Further, in this type of image forming apparatus, in order to supply the toner contained in the toner cartridge to the developing device, a supply means such as an agitator is provided in the toner cartridge, and the toner supplied to the developing device is further supplied with the toner cartridge. In order to return to the above, it has also been proposed to provide a return means such as an auger in the housing of the developing device. In this case, the toner can be circulated between the developing device and the toner cartridge by simultaneously operating the supply unit and the return unit. As a result, it is possible to prevent the toner from aggregating and becoming hard at one place, and as a result, the fluidity of the toner can be secured and the image quality can be improved (for example, see Patent Document 1). ).
JP-A-9-319201

  However, in this type of image forming apparatus, when the toner cartridge is replaced, the image quality may be deteriorated for the following reason. That is, it is known that the toner is deteriorated by repeating the image formation, and this is particularly noticeable in the case of non-magnetic one-component development because friction charging is performed by a developing roller as a developing unit. It can be seen. In addition, due to the deterioration of the toner, the charging performance of the toner may be lowered, and there may be a difference in chargeability depending on whether the toner is new or old. Here, if frictional charging is performed in a state where old and new toners are mixed, the deteriorated toner and the new toner will be inferior in charging performance, and the charge amount will be offset, so both toners will be charged to the same polarity. The new toner is positively charged and the deteriorated old toner is negatively charged. When this negatively charged toner adheres to a positively charged portion of the electrostatic latent image, that is, a portion that is originally so-called white solid, a so-called printing fog is generated.

  However, if there is a large amount of positively charged new toner in the vicinity of the developing roller, the new toner having a high charge amount preferentially adheres to the developing roller due to the mirror image force, and the old toner hardly adheres to the developing roller. Therefore, printing fog does not occur.

  However, when a large amount of old negatively charged toner exists in the vicinity of the developing roller and new toner enters, the old negatively charged toner is preferentially applied to the developing roller by rubbing with the new toner. It adheres and print fogging occurs. When a new toner cartridge is installed and new toner is supplied from there, this condition may be satisfied and printing fog may occur.

  Accordingly, the present invention provides an image forming apparatus that prevents frictional charging in a state where a large amount of deteriorated old toner is present and a small amount of new toner is mixed, and is less likely to cause print fogging. It was made for the purpose of providing.

The image forming apparatus of the present invention made to achieve the above object includes an image carrier on which an electrostatic latent image is formed on a surface, and a toner in which toner used for developing the electrostatic latent image is contained. A cartridge and a roller, and a toner contained in the toner cartridge is frictionally charged to adhere to the surface of the image carrier to develop the electrostatic latent image, and the toner cartridge is detachable is configured, at least the developing roller, a developing device that houses a supply roller for supplying the toner toward the developing roller, an image forming apparatus having the above toner cartridge on Symbol developing device mounted When the developing roller is in operation, the developing roller is operable regardless of whether or not it is rotating, and the toner is circulated between the developing device and the toner cartridge. Stage and, the toner cartridge certain time is mounted in the developing device, and an operation control means for operating the circulation means while stopping both of the developing roller and the supply roller, said circulation means Are provided in the toner cartridge and supply means for supplying the toner contained in the toner cartridge to the developing device, and the toner provided in the developing device and supplied to the developing device is returned to the toner cartridge. Return means, wherein the supply means is an agitator, and the return means circulates the toner supplied from the toner cartridge inside the developing device, and the circulated toner to the toner cartridge. It is characterized by being a return auger to return to .

In the present invention configured as described above, when the toner cartridge is attached to the developing device, the circulating means can operate with the developing roller stopped . Therefore , the toner can be circulated satisfactorily by stopping the developing roller and preventing the toner from being frictionally charged , and simultaneously operating the supply means and the return means as the circulation means. By performing such an operation when replacing the toner cartridge, it is possible to form an image while the toner is frictionally charged by the developing roller from a state where a small amount of old toner is uniformly mixed with a large amount of new toner. Therefore, in the present invention, it is possible to prevent the occurrence of printing fog by preventing frictional charging in a state where a large amount of deteriorated old toner is present and a small amount of new toner being mixed. Can do.

In addition, when the toner cartridge is replaced, the operation control unit operates the circulation unit while the developing roller is stopped for a predetermined time after the new toner cartridge is mounted in the developing device. Therefore, image formation can be started from a state in which a small amount of old toner is uniformly mixed with a large amount of new toner, and the occurrence of printing fog can be automatically prevented. Further, as described above, when the developing roller and the supply roller are provided, the new toner and the old toner may be rubbed and frictionally charged between the two to cause print fogging. On the other hand, in the present invention, since both the developing roller and the supply roller are stopped for the predetermined time, it is possible to better prevent the toner from being frictionally charged during the predetermined time.
Further, the image forming apparatus of the present invention includes an image carrier on which an electrostatic latent image is formed on a surface, a toner cartridge in which toner used for developing the electrostatic latent image is accommodated, and a roller shape. A developing roller configured to triboelectrically charge the toner contained in the toner cartridge to adhere to the surface of the image carrier and develop the electrostatic latent image; and the toner cartridge to be removable. with the developing roller, the toner supply roller for supplying the toner toward the developing roller to an image forming apparatus having a developing device that houses a position out of contact with the developing roller, the upper Symbol developing device When the cartridge is mounted, it can operate regardless of whether the developing roller is rotating or not, and toner is circulated between the developing device and the toner cartridge. Circulating control means, and operation control means for operating the circulating means while stopping only the developing roller of the developing roller and the supply roller for a certain time after the toner cartridge is mounted on the developing device, And the circulating means is provided in the toner cartridge and supplies the toner contained in the toner cartridge to the developing device; and the toner provided in the developing device and supplied to the developing device is supplied to the developing device. Return means for returning to the toner cartridge, the supply means is an agitator, and the return means is a supply auger for circulating the toner supplied from the toner cartridge inside the developing device. and the toner characterized in that in the return auger to return to the toner cartridge It may be. Also in this case, it is possible to automatically prevent the occurrence of printing fog as in the case of the above invention. In the present invention, since the developing roller and the supply roller are arranged in a non-contact manner, the toner is not rubbed and frictionally charged between them. Accordingly, the circulating means may be operated while only the developing roller of the developing roller and the supply roller is stopped for the certain time, and the toner is frictionally charged during the certain time even if such operation is performed. Can be prevented.

The present invention does not limit the type of toner, but the toner may be a non-magnetic one-component toner. Since the non-magnetic one-component toner is used after being frictionally charged, the above-described effect is more remarkable. Further, when the toner is a styrene-acrylic polymerized toner, the above-described effect is more remarkably exhibited because the above-mentioned fog is likely to occur as much as the chargeability is excellent. In addition, as described above, when the developing roller is stopped, the fluidity of the toner is hindered, and the circulation of the toner by the circulation means is slightly affected. It can be minimized.

Further, when the operation control means as described above is provided, the speed of the circulation means is greater when the developing roller is stopped than when the developing roller is operating. In this case, the following additional effects occur. That is, the new and old toners can be mixed more rapidly, and the start of image formation can be made quicker when the toner cartridge is replaced.

Further, in the case where the operation control means as described above is provided, the developing device may be configured to be detachable, and in this case, the following further effects are produced. In this case, the developing device can be replaced in accordance with the deterioration of the developing roller , and the maintainability is improved. The image carrier may be configured to be detachable. In this case, the image carrier can be replaced in accordance with the deterioration of the image carrier, and the maintainability is improved.

In the present invention, the toner cartridge outputs a driving force input unit to which a driving force is input from the main body side of the image forming apparatus, and outputs the driving force input to the driving force input unit to the return unit. And a possible driving force output unit. In this case, when the toner cartridge is mounted, the driving force is input to the driving force input unit from the main body side of the image forming apparatus, and the driving force is output to the returning means via the driving force output unit, thereby returning the toner cartridge. The means is driven. On the other hand, when the toner cartridge is removed, the driving force input unit and the driving force output unit are also detached together with the toner cartridge, so that the driving force is not transmitted to the return means. Therefore, in this case, it is possible to prevent the return means from being driven in a state where the toner cartridge is removed, and to prevent the toner from overflowing from the developing device.

  In this case, the driving force input unit and the driving force output unit may be linked to the supply unit. In this case, when the toner cartridge is mounted, since the return means and the supply means are interlocked, control becomes easier.

  Further, when the toner cartridge includes the driving force input unit and the driving force output unit as described above, the driving force input unit and the driving force output unit are disposed on the surfaces of the toner cartridge facing each other. May be. In this case, it becomes easy to design a drive system such as a gear arrangement in the vicinity of the driving force input unit and the driving force output unit, and the device can be easily downsized.

More specifically, in the developing device, the developing roller and the return means need to be arranged close to each other. Further, when a driving object such as a supply roller for supplying toner to the developing roller is arranged, it is very difficult to arrange a driving mechanism on one side surface of the developing device. Therefore, it is preferable to provide drive mechanisms on both side surfaces of the developing device. However, if the motor is also disposed on both sides of the developing device, the entire image forming apparatus becomes large. Therefore, if the driving force is transmitted from one side surface to the other side surface through the toner cartridge, the entire image forming apparatus can be driven appropriately without increasing the size.

Further, the process cartridge of the present invention is configured such that a toner cartridge in which toner used for developing an electrostatic latent image formed on the surface of the image carrier is accommodated is detachable, and is configured in a roller shape. the toner cartridge accommodated in the toner is frictionally charged to be adhered to the surface of the image bearing member, a developing roller for developing an electrostatic latent image, and a supply roller for supplying the toner toward the developing roller A process cartridge that is housed and detachable from the image forming apparatus, the supply auger circulating the toner supplied from the toner cartridge inside the process cartridge, and the return for returning the circulating toner to the toner cartridge comprising a auger, and when the toner cartridge is mounted, both of the developing roller and the supply roller Operable while stopped, and the toner in the process cartridge is characterized in that the return means for returning toward the toner cartridge, comprising a.

In the present invention configured as described above, when the toner cartridge is mounted, the return means can operate with the developing roller stopped . Therefore, the return roller can be operated to circulate the toner between the toner cartridge while the developing roller is stopped and the toner is not frictionally charged. If such an operation is performed at the time of replacement of the toner cartridge, the toner is adhered to the image carrier while the toner is frictionally charged by the developing roller from a state where a small amount of old toner is uniformly mixed with a large amount of new toner. be able to. Therefore, when the process cartridge of the present invention is used in an electrophotographic image forming apparatus, frictional charging is performed in a state where a small amount of new toner is mixed with a large amount of deteriorated old toner. Therefore, it is possible to satisfactorily prevent the occurrence of printing fog. In addition, when the developing roller and the supply roller are provided as described above, the new toner and the old toner may be rubbed and frictionally charged between the two to cause print fogging. In contrast, in the present invention, the return means can be operated while both the developing roller and the supply roller are stopped. Therefore, the return means is operated so that the toner is not charged by friction. It can be circulated better.
Further, the process cartridge of the present invention is configured such that a toner cartridge in which toner used for developing an electrostatic latent image formed on the surface of the image carrier is accommodated is detachable, and is configured in a roller shape. The toner contained in the toner cartridge is frictionally charged and adhered to the surface of the image carrier, and the developing roller for developing the electrostatic latent image and a supply roller for supplying the toner toward the developing roller are developed. A process cartridge that is housed in a position that is not in contact with the roller and is detachable from the image forming apparatus, the supply auger circulating the toner supplied from the toner cartridge inside the process cartridge; and the circulating toner A return auger for returning the toner cartridge to the toner cartridge, and when the toner cartridge is mounted, It is possible to operate with only the developing roller being stopped among the image roller and the supply roller, and provided with return means for returning the toner in the process cartridge toward the toner cartridge. May be.
Also in this case, it is possible to satisfactorily prevent the occurrence of printing fog. In the present invention, since the developing roller and the supply roller are arranged in a non-contact manner, the toner is not rubbed and frictionally charged between them. Therefore, in this case, the circulating means may be operated while only the developing roller of the developing roller and the supply roller is stopped. Even if such an operation is performed, the toner is kept without being frictionally charged. It can be circulated.

In the present invention, the type of toner is not particularly limited, but the toner may be a non-magnetic one-component toner. Since the non-magnetic one-component toner is used after being frictionally charged, the above-described effect is more remarkable. Further, when the toner is a styrene-acrylic polymerized toner, the above-described effect is more remarkably exhibited because the above-mentioned fog is likely to occur as much as the chargeability is excellent. Further, as described above, when the developing roller is stopped, the fluidity of the toner is hindered, and the return of the toner by the return means is affected to some extent, but if a polymerized toner having excellent fluidity is used, the influence is reduced. It can be minimized.

  Next, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a perspective view showing an appearance of a laser printer 1 as an image forming apparatus to which the present invention is applied. The laser printer 1 of the present embodiment forms an image with a positively chargeable nonmagnetic one-component toner (styrene-acrylic polymer toner).

  As shown in FIG. 1, a paper feed cassette 3 is attached to the lower part of a cover 2 that covers the main body of the laser printer 1 from the outer periphery, and the front surface of the cover 2 (that is, the surface disposed in front of the laser printer 1 when installed). ) Is provided with a cover 4 of the cover 2.

  The lid portion 4 is provided with finger hooking portions 4a above both left and right ends. By pulling the finger hooking portions 4a, the lid portion 4 can be opened to the front with the hinge 4b at the lower end as the center as shown in FIG. Further, as shown in FIG. 3, the paper feed cassette 3 is provided so as to be able to be pulled out toward the front, and the paper feed cassette 3 can be attached to and detached from the laser printer 1 by being drawn out in this way.

  Next, FIG. 4 is a longitudinal sectional view showing the internal configuration of the laser printer 1. 4 corresponds to a cross-sectional view taken along line AA in FIG. As shown in FIG. 4, a support plate 5 urged upward by a spring 6 is provided inside the paper feed cassette 3, and on the support plate 5 on the front side further above the support plate 5. A paper feed roller 9 is provided that separates sheets (not shown) as recording media held in a stacked state one by one and supplies them in the direction of the image forming unit 7. In addition, in the paper conveyance path from the paper supply roller 9 to the image forming unit 7, the conveyance roller 11 that conveys the paper in cooperation with the paper supply roller 9 and the paper conveyed by the conveyance roller 11 are fed. A guide 13 that turns back about 180 ° along the outer periphery of the roller 9 and a pair of registration rollers 14 and 15 that lock the leading edge of the paper by appropriately stopping and correct the skew of the paper are sequentially arranged. ing.

  The image forming unit 7 includes a photoconductor drum 21 as an image carrier provided in the photoconductor cartridge 20, and a transfer roller 22 as a transfer unit disposed opposite to the photoconductor drum 21. The sheet on which the toner image is formed as described later after passing between the photosensitive drum 21 and the transfer roller 22 is supplied to the fixing unit 31. In the fixing unit 31, the toner image formed on the sheet is sandwiched between the heating roller 33 and the pressing roller 35 and thermally fixed, and the sheet on which the image is fixed is further conveyed by a pair of conveying rollers 36 and 36. .

  The paper transported by the transport rollers 36 and 36 is guided to the upper side of the cover 2 by the guide 37 and discharged to a paper discharge tray 39 provided on the upper surface of the cover 2 by a pair of paper discharge rollers 38 and 38. A scanner unit 90 that exposes the photosensitive drum 21 with the laser beam L is disposed between the paper discharge tray 39 and the photosensitive cartridge 20.

  Next, the configuration of the image forming unit 7 and the scanner unit 90 will be described in more detail. The photoconductor cartridge 20 is rotatably provided with a photoconductor drum 21 having a photoconductive layer on its surface, and further includes a transfer roller 22 and a scorotron charger 23 as a charging unit that uniformly charges the surface of the photoconductor drum 21. It has. An electrostatic latent image is formed on the surface of the photosensitive drum 21 charged by the scorotron charger 23 by the laser light L incident from the scanner unit 90 through the exposure opening 20a. Subsequently, a developing roller 41 as a developing unit provided in the developing cartridge 40 described below supplies toner to the surface of the photosensitive drum 21, whereby the electrostatic latent image is developed. The toner attached to the photosensitive drum 21 in this manner is transferred to a sheet passing between the transfer roller 22 and an image is formed on the sheet by the above operation. Further, a paper dust collecting brush 24 to which a positive bias is applied is in contact with the surface of the photosensitive drum 21 after image formation, and the paper dust (negatively charged) adhering from the paper to the photosensitive drum 21 is contacted. It has been removed.

  As shown in FIG. 4, the developing roller 41 is rotatably supported by the developing cartridge 40, and is driven to rotate by a mechanism described later in contact with the photosensitive drum 21. The developing cartridge 40 includes a support portion 42 as a cartridge mounting portion that detachably supports the toner cartridge 60, and an opening 42 a through which toner is supplied from the toner cartridge 60 is formed in the support portion 42 ( (See FIG. 7). Further, the developing cartridge 40 is conveyed by an upper auger 43 and a lower auger 44 that circulate toner supplied from an opening 42 a provided in the central portion in the axial direction on both sides in the axial direction, and the upper auger 43 and the lower auger 44. A supply roller 45 that supplies the toner to the developing roller 41 and a developing blade 47 that frictionally charges the toner attached to the surface of the developing roller 41 by the supply roller 45 to form a thin layer of toner are provided. ing. An agitator 61 for agitating the supplied toner and supplying it to the developing cartridge 40 side is rotatably provided inside the toner cartridge 60.

  Next, the configuration of the scanner unit 90 will be described. The scanner unit 90 includes a polygon mirror 91 that deflects and scans a laser beam L generated by a laser light emitting unit (not shown), and mirrors 92 and 93 that return the laser beam L deflected to the polygon mirror 91 toward the photosensitive drum 21. It has. Further, an fθ lens 95 is fixed to the optical path of the laser light L from the polygon mirror 91 to the mirror 92, and a cylindrical lens 97 is fixed to the optical path of the laser light L from the mirror 92 to the mirror 93.

  With the above configuration, an electrostatic latent image can be formed on the surface of the photosensitive drum 21 by emitting the laser light L at an appropriate timing while rotating the polygon mirror 91 and the photosensitive drum 21. Then, as described above, the electrostatic latent image is developed with toner via the developing roller 41 and transferred onto a sheet, thereby enabling image formation by electrophotography.

  Next, as shown in FIG. 5, when the lid portion 4 is opened and the handle 25 of the photosensitive cartridge 20 is further pulled forward, the photosensitive cartridge 20 is integrated with the developing cartridge 40 and the toner cartridge 60, and the attachment / detachment opening 2a. To the outside of the main body of the laser printer 1. The attachment / detachment opening 2 a is an opening of the cover 2 that is closed by the lid 4.

  Further, as shown in FIG. 6, when the handle 62 of the toner cartridge 60 is rotated upward, the toner cartridge 60 is divided from the developing cartridge 40 as will be described later, and when the handle 62 is further pulled forward, FIG. As shown in FIG. 4, only the toner cartridge 60 can be taken out from the apparatus main body of the laser printer 1 through the attachment / detachment opening 2a.

  Furthermore, as shown in FIG. 8, when the handle 25 of the photosensitive cartridge 20 is pushed down, the leaf spring 26 that engages and fixes the developing cartridge 40 is pushed down, and the handle 62 of the toner cartridge 60 is further rotated upward. If the toner cartridge 60 and the developing cartridge 40 are pulled to the front without being moved, the toner cartridge 60 and the developing cartridge 40 are integrally separated from the apparatus body of the laser printer 1 through the attachment / detachment opening 2a without being divided. Can do.

  Next, the configuration of each part constituting the image forming unit 7 will be described. FIG. 9 is a left side view illustrating the configuration of the photoconductor cartridge 20. In the following description, the near side in FIG. 4 is defined as the left side. As shown in FIG. 9, the handle 25 of the photoconductor cartridge 20 is fixed to the photoconductor cartridge 20 via a leaf spring 26. The leaf spring 26 has a bent portion 26a bent upward in a stepwise manner. When the developing cartridge 40 is attached to the photosensitive cartridge 20, the bent portion 26a is formed at the lower edge of the support portion 42. By engaging, the photosensitive cartridge 20 and the developing cartridge 40 are connected. Therefore, when the handle 25 is pushed down as described above (see FIG. 8), the engagement between the bent portion 26a and the lower edge of the support portion 42 is released, and the developing cartridge 40 is attached to and detached from the photosensitive cartridge 20. It becomes possible.

  Further, the metal rotating shaft 21a of the photosensitive drum 21 protrudes from the photosensitive cartridge 20 to the left and right sides, and rotates integrally with the photosensitive drum 21 from the rear (mounting direction side) end of the photosensitive cartridge 20. The gear 21b is exposed.

  On the other hand, as shown in FIG. 10, a guide groove 121 that guides the rotating shaft 21a is formed on the left inner wall surface of the main body of the laser printer 1, and a gear 121b that meshes with the gear 21b is provided. The gear 121b is configured to be drivable by a drum motor 122 (see FIG. 16). When the photoconductor cartridge 20 is mounted, the gears 21b and 121b are engaged with each other to transmit a driving force from the main body side to the photoconductor drum 21. It becomes possible.

  Next, FIG. 11 is a left side view illustrating a state in which the toner cartridge 60 is attached to the developing cartridge 40. As shown in FIG. 11, a drive shaft 51 to which a driving force is transmitted from the drive shaft 151 on the main body side is provided on the left side surface of the developing cartridge 40. The drive shaft 151 is provided with a flat plate-like convex portion 151a on the end surface, and the drive shaft 51 is formed as a cylindrical concave portion into which the drive shaft 151 can be fitted, and a projection 51a that can be engaged with the flat plate-like convex portion 151a is formed. Both constitute a so-called drive coupling.

  As shown in FIG. 11, a gear 51 b that rotates integrally with the drive shaft 51 is formed. The gear 51 b includes a gear 41 a that rotates together with the developing roller 41 and a gear 45 a that rotates together with the supply roller 45. Are engaged.

  Further, the toner cartridge 60 is configured as follows, and can be switched between connection and disconnection with the developing cartridge 40. 12A and 12B show a state in which the handle 62 of the toner cartridge 60 is disposed at a position rotated upward (hereinafter referred to as a dividing position) as shown in FIG. 12A is a view of the support portion 42 of the developing cartridge 40 as viewed from the toner cartridge 60 side, and FIG. 12B is a view of the toner cartridge 60 as viewed from the support portion 42 side.

  As shown in FIG. 12B, the toner cartridge 60 includes a long cylindrical inner cylinder 63 in which toner is accommodated, and an outer cylinder 64 that is externally fitted to the center of the inner cylinder 63. Yes. The outer cylinder 64 is non-rotatably attached to the support portion 42 by engaging a protrusion 64 a protruding toward the support portion 42 with a long groove 42 b formed on the inner wall surface of the support portion 42. The inner cylinder 63 is integrally formed with the handle 62 described above, and is configured to be rotatable inside the outer cylinder 64 in accordance with the operation of the handle 62.

  Also, as shown in FIG. 12A, a shutter 48 made of a metal plate is disposed inside the support portion 42. The shutter 48 is supported at both ends by rails 42c formed on the inner wall surface of the support portion 42, thereby closing the opening 42a of the support portion 42 as shown in FIG. It is arranged so as to be movable in the inner circumferential direction of the support portion 42 between a position (see FIG. 12C) arranged to be displaced upward.

  Four protrusions 63 a are formed on the surface of the inner cylinder 63 to sandwich the vicinity of both ends of the shutter 48 from both sides in the circumferential direction. For this reason, when the shutter 48 is moved according to the rotation of the inner cylinder 63 and the handle 62 is rotated to the dividing position, as shown in FIG. 12 (A), the shutter 48 is a position that closes the opening 42a. It is arranged. The long groove 42b described above is further formed below the shutter so as not to overlap the shutter 48 disposed at this position. Moreover, the opening part 42a is comprised by the rectangular shape long in a horizontal direction, and the rectangular frame-shaped sponge 49 surrounding the opening part 42a is affixed on the inner wall surface of the support part 42 of the circumference | surroundings.

  An opening 64b having the same shape as the opening 42a is formed in a portion of the outer cylinder 64 that faces the opening 42a when the protrusion 64a is engaged with the long groove 42b. A shaped sponge 65 is affixed. The inner cylinder 63 also has an opening 63b having the same shape as the opening 64b. However, as shown in FIG. 12B, when the handle 62 is disposed at the dividing position, the opening 64b. And the opening 63b do not overlap at all. For this reason, even when the toner cartridge 60 is removed, the toner inside does not spill.

  Then, when the protrusion 64a is engaged with the long groove 42b and the handle 62 of the toner cartridge 60 is rotated downward as shown in FIG. 8 (hereinafter, this position of the handle 62 is referred to as a coupling position), FIG. 12 (D), the opening 64b and the opening 63b overlap. At this time, the shutter 48 is moved by the protrusion 63a to the upper part of the opening 42a as shown in FIG. 12C, so that the opening 64b and the opening 42a communicate with each other, and the toner cartridge 60 and the developing cartridge. The toner can be supplied to 40.

  Further, at this time, the sponge 49 and the sponge 65 are in close contact with each other, and the engaging portion 63c integrally formed on the outer peripheral surface of the inner cylinder 63 is engaged with the rail 42c, so that the openings 64b and 42a are sealed. As a result, toner does not spill outside. Further, the engagement between the engaging portion 63c and the rail 42c connects the developing cartridge 40 and the toner cartridge 60, and it is possible to attach and detach them together as described above (see FIG. 8). Conversely, by operating the handle 62 to rotate the inner cylinder 63 and releasing the engagement between the engaging portion 63c and the rail 42c, the developing cartridge 40 and the toner cartridge 60 are separated, as described above. Only the toner cartridge 60 can be taken out (see FIG. 7).

  A gear 61b that rotates integrally with the rotation shaft 61a of the agitator 61 is disposed outside the right end of the inner cylinder 63, and the toner cartridge 60 is mounted at a position facing the gear 61b of the support portion. Sometimes the gear 53 that meshes with the gear 61b is exposed. As can be seen from the right side view of the developing cartridge 40 and the toner cartridge 60 shown in FIG. 13, the gear 53 is engaged with gears 43a and 44a that rotate integrally with the upper auger 43 and the lower auger 44, respectively. Further, as shown in FIGS. 10 and 11, the rotating shaft 61a of the agitator 61 constitutes a so-called drive coupling with the drive shaft 161 on the main body side. That is, the drive shaft 161 is provided with a flat plate-like convex portion 161a on the end surface, and the rotating shaft 61a is formed as a cylindrical concave portion into which the drive shaft 161 can be fitted, and a projection 61c that can be engaged with the flat plate-like convex portion 161a is formed. Has been.

  For this reason, when the driving force is transmitted from the driving shaft 161 to the rotating shaft 61a, the agitator 61 is rotated by the driving force, and the driving force is sequentially transmitted to the gear 61b, the gear 53, and the gear 43a or 44a. The auger 43 and the lower auger 44 can be rotated.

  As shown in FIG. 10, a gear 172 that can rotate integrally with the drive shaft 151 meshes with a gear 171 fixed to the rotation shaft of the developing motor 170, and the gear 172 is connected to the drive shaft 161. A gear 174 that rotates integrally is engaged with the gear 174 via a gear 173. However, an electromagnetic clutch 175 (see FIG. 16) is provided between the drive shaft 151 and the gear 172 so that connection / disconnection can be switched. For this reason, when the electromagnetic clutch 175 is switched to the connection side, the driving force of the developing motor 170 is output from both the drive shafts 151 and 161, and the developing roller 41, the supply roller 45, the upper auger 43, the lower auger 44, and the supply The roller 45 and the agitator 61 can be driven simultaneously. Further, when the electromagnetic clutch 175 is switched to the non-connection side, the driving force of the developing motor 170 is output only from the driving shaft 161, and the developing roller 41 and the supply roller 45 are stopped and the upper auger 43 and the lower auger 44 are stopped. , And the agitator 61 can be driven.

  The drive shafts 151 and 161 are provided so as to protrude / retract, and are connected to a link mechanism (not shown) so as to protrude or retract in conjunction with closing or opening of the lid 4. When the lid portion 4 is opened, they are retracted, and the engagement between the drive shafts 151 and 161, the drive shaft 51, and the rotation shaft 61a is released. Therefore, the photosensitive cartridge 20, the developing cartridge 40, and the toner cartridge 60 can be attached and detached. On the contrary, when the lid portion 4 is closed, they protrude and the drive shafts 151 and 161 are engaged with the drive shaft 51 and the rotation shaft 61a. For this reason, it is possible to drive each of the aforementioned parts.

  Next, FIG. 14 is a longitudinal sectional view showing a state where the toner cartridge 60 is mounted on the developing cartridge 40. As shown in FIG. 14, the agitator 61 is made of a resin material such as ABS resin having flexibility, and the following members are integrally formed. That is, the gear 61b and the rotation shaft 61a, the blade member 61d provided on the rotation shaft 61a, the flexible film member 61e provided on the blade member 61d, and the wiper support portion 61f provided on the rotation shaft 61a. , It is configured integrally.

  The wiper support portion 61f is provided so as to protrude in a direction opposite to the protruding direction of the blade member 61d at both axial ends of the rotating shaft 61a. A wiper member 67 for wiping a toner remaining amount detection window 63d described below is fixed to each wiper support portion 61f. Each wiper member 67 is disposed so as to elastically contact the left and right inner wall surfaces of the inner cylinder 63 in order to wipe the remaining toner amount detection window 63d. The toner remaining amount detection window 63d is provided on the lower rear side of the inner cylinder 63 so as to face the left and right wall surfaces of the inner cylinder 63. Further, as shown in FIGS. 11 and 13, a circular light passage portion 42d is provided at a portion of the support portion 42 that faces the toner remaining amount detection window 63d.

  Next, as shown in FIG. 15, the upper auger 43 and the lower auger 44 are formed with helical teeth 43b and 44b, respectively, and operate as follows by the rotation. That is, the lower auger 44 conveys the toner discharged from the opening 42a by the rotation of the agitator 61 in the left-right direction in the developing cartridge 40, and the upper auger 43 centers the toner accumulated on the left and right sides of the developing cartridge 40 in the center. The collected toner is returned to the toner cartridge 60 from the opening 42a.

  By this operation, the toner can be circulated in the developing cartridge 40 and the toner can also be circulated between the developing cartridge 40 and the toner cartridge 60, so that the deteriorated toner is prevented from being concentrated and fixed to a part. The fluidity of the toner can be ensured. Note that the toner transport directions by the upper auger 43 and the lower auger 44 are indicated by arrows in FIG.

  As shown in FIGS. 14 and 15, a partition wall 55 is provided between the upper auger 43 and the lower auger 44 for smooth conveyance of the toner. FIG. 15 is a cross-sectional view of the developing cartridge 40 cut along the arrangement direction of the upper auger 43 and the lower auger 44. The configuration (gears 43a, 44a, etc.) disposed outside the developing cartridge 40 is shown in FIG. Illustration is omitted.

  Also, as shown in FIGS. 12B and 14, a pair of spring receiving portions 66, 66 whose center in the circumferential direction is recessed are formed on the left and right on the surface of the inner cylinder 63 slightly above both sides of the handle 62. Has been. As shown in FIG. 2, a pair of pressing members 71, 71 urged in a protruding direction by a spring (not shown) is disposed on the inner surface of the lid portion 4, and the spring receiving portions 66, 66 close the lid portion 4. When pressed, it receives a pressing force from the pressing members 71, 71. The cartridges 20, 40, 60 are securely fixed in the apparatus by this pressing force. Further, an interference member 72 protrudes between the pressing members 71, 71, and if the handle 62 is not disposed at the coupling position, the handle 62 and the interference member 72 may interfere with each other to close the lid portion 4. It is configured not to be able to.

  Next, the control system of the laser printer 1 will be described. As shown in FIG. 16, the laser printer 1 includes a toner cartridge via a cover sensor 198 such as a limit switch that detects opening / closing of the lid 4 and the toner remaining amount detection window 63d and the light passage 42d. And an empty sensor 199 such as a photocoupler that optically detects the presence or absence of toner in the toner cartridge 60. In the present embodiment, the empty sensor 199 includes a light emitting element 199a provided on the left inner wall surface of the main body of the laser printer 1 as shown in FIG. 10, and a right inner wall surface of the main body of the laser printer 1 facing the light emitting element 199a. And a light receiving element (not shown).

  The control unit 200 of the laser printer 1 is configured as a known microcomputer in which a CPU 201, a ROM 202, a RAM 203, and an I / O port 204 are connected by a bus 205. The I / O port 204 is supplied with signals from the cover sensor 198 and empty sensor 199 described above, as well as a scanner unit 90, a drum motor 122, a developing motor 170, and an electromagnetic clutch 175. They are connected via 211, 212, 213, and 214. In addition to the above, the I / O port 204 is connected to various known mechanisms such as an operation panel and a buzzer.

  FIG. 17 is a flowchart illustrating a process executed by the CPU 201 of the control unit 200 based on a program stored in the ROM 202. This process is repeatedly executed at a predetermined timing after the laser printer 1 is powered on.

  When the process is started, first in S1 (S represents a step: the same applies hereinafter), based on the detection signal of the empty sensor 199, toner empty (toner is consumed and light frequently passes between the light passing portions 42d and 42d). It is determined whether or not the state has passed. That is, since the toner is agitated by the agitator 61 in the inner cylinder 63, light may pass between the light passing portions 42d and 42d even when there is sufficient toner. The passing period will be longer. Therefore, in S1, it is determined whether or not the toner is empty based on the length of the period during which light passes between the light passage portions 42d and 42d. If the toner is not empty (S1: N), the process proceeds to S2, and a normal process such as forming an image on a sheet based on the input data is executed, and the process returns to S1. Until the toner becomes empty, the normal processing is continued by repeating the processing of S1 and S2. For example, at the time of image formation, the electromagnetic clutch 175 is switched to the connection side and the developing motor 170 is driven, whereby the developing roller 41, the supply roller 45, the upper auger 43, the lower auger 44, and the agitator 61 are simultaneously driven. The

  When the toner is empty (S1: Y), the process proceeds to S3, and it is notified by the display on the operation panel and the alarm sound by the buzzer that the toner is empty. In many cases, toner empty is detected during image formation on a sheet, but in subsequent S4, image formation is prohibited after the job being executed is completed.

  Further, in subsequent S6, the process waits until the lid 4 is opened (S6: N). That is, in response to the notification in S3, the user opens the lid 4 to replace the toner cartridge 60, but waits until the opening operation of the lid 4 is detected by the cover sensor 198.

  If the cover part 4 is opened (S6: Y), it will wait until the cover part 4 is closed by the user in S7 (S7: N). Normally, the toner cartridge 60 is replaced by the user during this period. Therefore, if the lid 4 is closed during the standby in S7 (S7: Y), it is considered that a new toner cartridge 60 has been installed by the user, and the process proceeds to S8.

  In S8, the electromagnetic clutch 175 is switched to the non-connection side and the developing motor 170 is driven, so that the upper auger 43, the lower auger 44, and the agitator 61 are stopped while the developing roller 41 and the supply roller 45 are stopped. The driving process is executed for a predetermined time. By this processing, the old toner remaining in the developing cartridge 40 and the new toner accommodated in the toner cartridge 60 can be circulated and mixed together. After this process is executed for a predetermined time, in S9, the prohibition of image formation set in S4 is released, and the process returns to S1 described above.

  Through the above processing, in this embodiment, when a new toner cartridge 60 is mounted, the upper auger 43, the lower auger 44, and the agitator 61 can be driven for a predetermined time to mix old and new toner. Moreover, since the developing roller 41 and the supply roller 45 are stopped during this process, the toner is not frictionally charged. For this reason, in this Embodiment, generation | occurrence | production of printing fog can be prevented as follows.

  When the non-magnetic one-component toner (especially styrene-acrylic polymerized toner) whose charging performance is deteriorated due to deterioration as in the laser printer 1 is frictionally charged, if the old and new toners are rubbed together, the deterioration occurs. The charged toner and the new toner are not superior or inferior in charging performance, and the charge amount is shifted. Therefore, both toners are not charged to the same polarity, and the new toner is charged positively and the deteriorated old toner is negatively charged. However, if a large amount of positively charged new toner exists in the vicinity of the developing roller 41, the new toner having a high charge amount preferentially adheres to the developing roller 41 due to the mirror image force, and the negatively charged toner is Printing fog does not occur even if it exists.

  However, when a large amount of old negatively charged toner is present in the vicinity of the developing roller 41, new toner enters the developing roller 41 preferentially to the negatively charged toner due to the mirror image force. It adheres and print fogging occurs. In a conventional laser printer, such a condition is satisfied when the toner cartridge is replaced, and print fogging may occur.

  In contrast, in the present embodiment, when a new toner cartridge 60 is mounted, the process of S8 can be executed to mix old and new toner without performing frictional charging. Therefore, the toner can be frictionally charged by driving the developing roller 41 and the supply roller 45 from a state where a small amount of old toner is uniformly mixed with a large amount of new toner. Therefore, in this embodiment, it is possible to prevent the occurrence of print fog by preventing frictional charging in a state where a large amount of deteriorated old toner is present and a small amount of new toner is mixed. can do. If the rotation speed of the developing motor 170 in S8 is made higher than that during normal image formation, the new and old toners can be mixed more rapidly. In this case, it is possible to speed up the so-called image formation that enables the normal image forming process (S2) to be performed after the toner cartridge 60 is replaced.

  In this embodiment, when the toner cartridge 60 is detached from the developing cartridge 40, the driving force is not transmitted to the upper auger 43 and the lower auger 44. If the upper auger 43 and the lower auger 44 are driven with the toner cartridge 60 removed, the toner in the developing cartridge 40 may overflow to the outside. In this embodiment, the toner cartridge 60 is developed. Since the upper auger 43 and the lower auger 44 are not driven unless the cartridge 40 is mounted, it is possible to satisfactorily prevent the toner from overflowing as described above.

  In the above embodiment, the developing cartridge 40 is the developing device and the process cartridge, the agitator 61 is the supply means, the upper auger 43 and the lower auger 44 are the return means, and the agitator 61, the upper auger 43, and the lower auger 44 are the returning means. The circulation means includes an upper auger 43 as a return auger, a lower auger 44 as a supply auger, a control unit 200 as an operation control means, a gear 61b as a driving force output part, and a portion constituting the drive coupling of the rotary shaft 61a. Each corresponds to a driving force input unit.

  The present invention is not limited to the above-described embodiment, and can be implemented in various forms without departing from the gist of the present invention. For example, in the above embodiment, the cover sensor 198 detects that the toner cartridge 60 has been replaced, but it may be detected by the empty sensor 199. The toner cartridge 60 is provided with an IC tag or the like, and the laser printer side Detection may be performed by providing an IC tag reader or the like.

  In the above embodiment, when the new toner cartridge 60 is mounted, the developing roller 41 and the supply roller 45 are stopped to mix the old and new toner (S8). In the case of adopting a configuration such as this, it is conceivable that only the developing roller 41 is stopped and the same processing is performed.

  18A is a left side view illustrating a state in which the toner cartridge 60 according to the second embodiment is mounted on the developing cartridge 40, and FIG. 18B is a hidden gear in FIG. 18A. FIG. FIG. 19 is a longitudinal sectional view showing the internal configuration of the toner cartridge 60 and the developing cartridge 40. This embodiment differs from the above-described embodiment (first embodiment) in the following points, and the other configuration is the same. In FIG. 18 and FIG. 19, parts similar to those in the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

  As shown in FIGS. 18A and 18B, in this embodiment, the gear 51b that rotates integrally with the drive shaft 51 meshes only with the gear 41a that rotates integrally with the developing roller 41, and the supply roller 45 It does not mesh with the gear 45a that rotates integrally. A gear 61g that rotates integrally with the rotation shaft 61a of the agitator 61 is disposed outside the left end of the inner cylinder 63. The gear 61g is connected to gears 68 and 69 provided in the developing cartridge 40. Meshes with the gear 45a. Therefore, when the driving force is transmitted from the driving shaft 151 to the driving shaft 51, the developing roller 41 can be rotated. When the driving force is transmitted from the driving shaft 161 to the rotating shaft 61a, the supply roller 45, the agitator 61, and the upper auger. 43 and the lower auger 44 can be rotated.

  Further, as shown in FIG. 19, the supply roller 45 is accommodated in a position where it is not in contact with the developing roller 41 with a gap. Therefore, even if only the developing roller 41 is stopped and the supply roller 45, the agitator 61, the upper auger 43, and the lower auger 44 are rotated, the toner is not rubbed between the developing roller 41 and the supply roller 45. The toner is not triboelectrically charged. Therefore, also in this embodiment, the laser printer 1 main body can obtain the same effect by executing the same processing as that of the first embodiment. That is, in S8, the electromagnetic clutch 175 is switched to the non-connection side and the developing motor 170 is driven, so that the developing roller 41 is stopped and the supply roller 45, the upper auger 43, the lower auger 44, and the agitator 61 are stopped. The process of driving is executed for a predetermined time. During this time, old and new toner can be mixed without frictionally charging the toner.

  Furthermore, the present invention can be applied to various electrophotographic image forming apparatuses such as a copying machine, a facsimile machine, and a color laser printer, and the image carrier may be a photosensitive belt or other than the photosensitive body. It may be an image carrier. The present invention can also be applied to an image forming apparatus provided with a so-called intermediate transfer belt. In this case, the intermediate transfer belt also corresponds to a transfer unit.

  Furthermore, the photoconductor cartridge 20 and the developing cartridge 40 may be fixed to the main body of the laser printer 1, and the photoconductor cartridge 20 and the developing cartridge 40 may be configured as an integral process cartridge. However, in the above embodiment, since the photosensitive cartridge 20 and the developing cartridge 40 are configured to be detachable individually, they can be replaced as appropriate, and the maintenance is excellent.

1 is a perspective view illustrating an appearance of a laser printer to which the present invention is applied. It is a perspective view showing the operation | movement which opens the cover part of the laser printer. It is a perspective view showing the operation | movement which pulls out the paper feed cassette of the laser printer. It is a longitudinal cross-sectional view showing the internal structure of the laser printer. It is a longitudinal cross-sectional view showing operation which takes out each cartridge of the laser printer integrally. It is a longitudinal cross-sectional view showing operation which cuts off the toner cartridge and developing cartridge of the laser printer. It is a longitudinal cross-sectional view showing operation which takes out only the toner cartridge of the laser printer. It is a longitudinal cross-sectional view showing operation which takes out the developing cartridge and toner cartridge of the laser printer integrally. FIG. 6 is a left side view illustrating a configuration of a photosensitive cartridge of the laser printer. It is explanatory drawing showing the structure of the left inner wall face of the laser printer main body. FIG. 3 is a left side view illustrating a state where the toner cartridge is attached to the developing cartridge. FIG. 4 is an explanatory diagram illustrating a configuration of a mechanism that switches connection / disconnection between the developing cartridge and the toner cartridge. FIG. 4 is a right side view illustrating a state where a toner cartridge is attached to the developing cartridge. FIG. 3 is a longitudinal sectional view illustrating a state where a toner cartridge is attached to the developing cartridge. It is explanatory drawing showing the structure and operation | movement of the auger of the developing cartridge. It is a block diagram showing the structure of the control system of the said laser printer. It is a flowchart showing the process performed with the control system. FIG. 6 is a left side view illustrating a state where a toner cartridge according to a second embodiment is mounted on a developing cartridge. FIG. 3 is a longitudinal sectional view illustrating the internal configuration of the toner cartridge and the developing cartridge.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Laser printer 2a ... Removable port 4 ... Cover part 7 ... Image forming part 20 ... Photoconductor cartridge 21 ... Photoconductor drum 22 ... Transfer roller 40 ... Developing cartridge 41 ... Developing roller 42 ... Supporting part 42a, 63b, 64b ... Opening Part 42d: Light passage part 43 ... Upper auger 44 ... Lower auger 43b, 44b ... Spiral tooth 45 ... Supply roller 47 ... Developing blade 51, 151, 161 ... Drive shaft 55 ... Partition wall 60 ... Toner cartridge 61 ... Agitator 61a ... Rotation Shaft 61b ... Gear 62 ... Handle 63 ... Inner cylinder 63d ... Toner remaining detection window 64 ... Outer cylinder 90 ... Scanner unit 170 ... Developing motor 175 ... Electromagnetic clutch 198 ... Cover sensor 199 ... Empty sensor 200 ... Control unit L ... Laser light

Claims (14)

An image carrier on which an electrostatic latent image is formed on the surface;
A toner cartridge in which toner used for developing the electrostatic latent image is stored;
A developing roller configured to form a roller, frictionally charge the toner contained in the toner cartridge and adhere to the surface of the image carrier, and develop the electrostatic latent image;
A developing device in which the toner cartridge is configured to be detachable, and contains at least the developing roller and a supply roller for supplying toner toward the developing roller;
An image forming apparatus comprising:
When the toner cartridge on Kigen image device is attached, the developing roller is operable irrespective of whether the rotating operation circulates the toner between the developing device and the toner cartridge Circulation means,
An operation control means for operating the circulation means while stopping both the developing roller and the supply roller for a certain period of time after the toner cartridge is mounted on the developing device;
Equipped with a,
The circulation means is provided in the toner cartridge, and supply means for supplying the toner contained in the toner cartridge to the developing device; and the toner provided in the developing device and supplied to the developing device is supplied to the toner cartridge. A return means for returning to
The supply means is an agitator,
The image forming apparatus characterized in that the return means is a supply auger that circulates toner supplied from the toner cartridge inside the developing device and a return auger that returns the circulated toner to the toner cartridge. apparatus. An image carrier on which an electrostatic latent image is formed on the surface;
A toner cartridge in which toner used for developing the electrostatic latent image is stored;
A developing roller configured to form a roller, frictionally charge the toner contained in the toner cartridge and adhere to the surface of the image carrier, and develop the electrostatic latent image;
A developing device in which the toner cartridge is configured to be detachable, and a supply roller that supplies toner toward the developing roller together with at least the developing roller is housed in a position not in contact with the developing roller;
An image forming apparatus comprising:
When the toner cartridge on Kigen image device is attached, the developing roller is operable irrespective of whether the rotating operation circulates the toner between the developing device and the toner cartridge Circulation means,
An operation control means for operating the circulation means while only the developing roller of the developing roller and the supply roller is stopped for a certain period of time after the toner cartridge is mounted on the developing device;
Equipped with a,
The circulation means is provided in the toner cartridge, and supply means for supplying the toner contained in the toner cartridge to the developing device; and the toner provided in the developing device and supplied to the developing device is supplied to the toner cartridge. A return means for returning to
The supply means is an agitator,
The image forming apparatus characterized in that the return means is a supply auger that circulates toner supplied from the toner cartridge inside the developing device and a return auger that returns the circulated toner to the toner cartridge. apparatus.   The image forming apparatus according to claim 1, wherein the toner is a non-magnetic one-component toner.   The image forming apparatus according to claim 3, wherein the toner is a styrene-acrylic polymerized toner.   5. The speed of operation of the circulating means is higher when the developing roller is stopped than when the developing roller is operating. Image forming apparatus.   The image forming apparatus according to claim 1, wherein the developing device is configured to be detachable.   The image forming apparatus according to claim 1, wherein the image carrier is configured to be detachable.   The toner cartridge includes a driving force input unit to which a driving force is input from the main body side of the image forming apparatus, and a driving force output unit capable of outputting the driving force input to the driving force input unit toward the return means. The image forming apparatus according to claim 1, wherein the image forming apparatus includes:   9. The image forming apparatus according to claim 8, wherein the driving force input unit and the driving force output unit are interlocked with the supply unit.   The image forming apparatus according to claim 8, wherein the driving force input unit and the driving force output unit are disposed on mutually opposing surfaces of the toner cartridge. A toner cartridge in which toner used for developing an electrostatic latent image formed on the surface of the image carrier is accommodated is detachable;
Constructed in a roller shape, the toner contained in the toner cartridge is frictionally charged and adhered to the surface of the image bearing member, and the electrostatic latent image is developed, and the toner is supplied to the developing roller. A supply roller that houses,
A process cartridge that can be attached to and detached from an image forming apparatus,
A supply auger that circulates the toner supplied from the toner cartridge inside the process cartridge; and a return auger that returns the circulated toner to the toner cartridge; and when the toner cartridge is mounted, A return means operable to stop both the developing roller and the supply roller and return the toner in the process cartridge toward the toner cartridge;
A process cartridge characterized by comprising. A toner cartridge in which toner used for developing an electrostatic latent image formed on the surface of the image carrier is accommodated is detachable;
Configured to roller-shaped, the toner cartridge accommodated in the toner is frictionally charged to be adhered to the surface of the image carrier, along with the developing roller for developing the electrostatic latent image, the toner toward the developing roller The supply roller to be supplied is accommodated in a position that is not in contact with the developing roller ,
A process cartridge that can be attached to and detached from an image forming apparatus,
A supply auger that circulates toner supplied from the toner cartridge inside the process cartridge; and a return auger that returns the circulated toner to the toner cartridge, and when the toner cartridge is mounted, Returning means that can operate with only the developing roller out of the developing roller and the supply roller stopped, and returns the toner in the process cartridge toward the toner cartridge;
A process cartridge characterized by comprising. 13. The process cartridge according to claim 11 , wherein the toner is a non-magnetic one-component toner . The toner is a styrene - claims 1 to 3 process cartridge wherein the an acrylic polymer toner.

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